Cabinet with self-closing doors



July 21, 1959 P. P. EENDER CABINET WITH SELF-CLOSING DOORS 3Sheets-Sheet 1 Filed June 18, 1958 E2 INVENTOR. PAUL P. BENDER ATTORNEYSJuly 21, 1959 P. P. BENDER 2,895,779

CABiNET WITH SELF-CLOSING DOORS Filed June 18, 1.958

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ATTORNEYS July 21, 1959 P. P. BENDER 2,395,779

CABINET WITH SELF-CLOSING DOORS Filed June 18, 1958 3 Sheets-Sheet 3 o II INVEN R PAUL P. BENDER United States Patent This invention relates toa door construction for storage and display cabinets, and itparticularly relates to a V self-closing type of door construction.

Display cabinets having transparent windows or doors are used for manydifferent purposes both in the home and in commercial installations.They are very frequently used in restaurants or food stores fordisplaying the foods in full view of the customer while yet maintainingsuch foods free from contamination by dust, dirt, insects and the likepresent in the atmosphere. These cabinets are also generallyrefrigerated. For best efficiency, the doors on these cabinets areusually of the sliding panel type, which makes it difiicult to get intothe cabinet to clean it. Furthermore, food crumbs and dust tend toaccumulate in the grooves and tracks generally used for sliding doors.Consequently, it is highly desirable that these doors be removable sothat the grooves and tracks may be cleaned. The removal of the doorsalso permits easier access into the cabinet itself so that all portionsthereof may also be thoroughly cleaned.

Another problem inherent in the use of sliding doors or panels is theproblem of keeping them closed at all times except when the food orother articles are being inserted or removed. Often the person using thecabinet will forget to slide the door back into closed position; atother times, both hands will be full so that he cannot close the door atthat time and, thereafter, may forget to do so.

It is one object of the present invention to overcome the above andother diificulties by providing a removable sliding door constructionwherein the doors automatically close when released.

Another object of the present invention is to provide a sliding doorconstruction wherein the doors may be easily removed and inserted andwhen inserted will be in position for self-actuated closing.

Another object of the present invention is to provide a self-closingsliding door construction wherein the doors will return to closedposition at an even and constant velocity, thereby eliminating anysudden and violent shock action which might cause breakage of the doors;especially when such doors include a transparent glass pane or the like.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings, wherein:

Fig. 1 is a front perspective view of a display cabinet embodying thepresent invention;

Fig. 2 is a view partly in elevation and partly in section, takensubstantially on line 2-2 of Fig. 1, with parts broken away, and showingthe sliding door arrangement;

Fig. 3 is a fragmentary, top perspective view'of the channel member andself-closing arrangement for closing one of the sliding doors;

Fig. 4 is a fragmentary sectional view showing one of the doors beinginserted into the upper track;

2,895,779: Patented July 21, 1959 Fig. 5 is a view similar to Fig. 4 butshowing the door in closed position with the spring coil behind it;

Fig. 6 is a view similar to Figs. 4 and 5 but showing the inserted doorin partially open position with the spring of the coil extended;

Fig. 7 is a side elevational view of a second form of door embodying thepresent invention;

Fig. 8 is a side elevational view of a third form of door embodying thepresent invention;

Fig. 9 is a view similar to Figs. 7 and 8, of the door shown in Figs. 1to 6; the sloped inclination of the top edge being somewhat exaggeratedfor greater clarity; and

Fig. 10 is an enlarged front view, partly in section and partly inelevation, with parts broken away, of the front of the case illustratedin Fig. 1; here, too, the slope of the top edges of the doors beingslightly exaggerated for greater clarity.

Referring now in greater detail to the figures of the drawings whereinsimilar reference characters refer to similar parts, there is shown acabinet, generally designated 10, which comprises a base portion 12 inwhich is provided a refrigerated chamber closed by doors 14, a sideportion provided with shelves 16, a water fountain 18 below the shelves16 and a compressor unit 19 below the water fountain. The compressor 19is operatively connected to refrigerator coils (not shown) in thechamher in the base portion, and these refrigerator coils supply coldair not only to the chamber in the base but are also associated withconduits which carry the cold air up to vents (not shown) in theinterior of a food display case 20. Vents (not shown) are also providedin the food case to carry the warmed air down through correspondingducts (not shown) back to the refrigerator coils whereby a cyclic systemis effected.

The food display case 20 has an open front defined by a framework 22which includes top frame member 24, side frame members 26 and 28 andcounter portion 30 at the bottom. Extending across the open front at thecenter thereof is a bar 32, this bar beingconnected at one end to framemember 26 and at the other end to frame member 28.

Within the case 20 are provided a series of vertically spaced movableshelves 34 while at the bottom are pro vided a number of trays 36. Theshelves 34 and trays 36 are shown for purposes of illustration; however,any arrangement of shelves, trays or other desirable supports may beused and the case may even be empty if desired.

The bar 32 divides the case into what is, in effect, two compartmentswith a pair of sliding glass doors or panels closing each compartment.

The doors for the upper compartment are indicated at 38 and 40 and thedoors for the lower compartment are indicated at 42 and 44. Each doorcomprises a frame in which a glass pane is fixed and a handle isprovided on the frame at one side, as at 46, 48, 50 and 52. Each door isslidable in an individual channel at its upper edge, such channels beingshown at 54, 56, 58 and 60 respectively. (Note Fig. 2.)

The channels 54 and 56 are preferably formed from an integral striphaving three spaced vertical walls 62, 64 and 66 with an inwardly turnedflange on the bottom edge of each wall, as at 68, 70 and 72respectively. The channels 58 and 60 are similarly formed by a striphaving three vertical walls 74, 76 and 78 each of which has an inwardlyextending bottom flange respectively indicated at 8'0, 82 and 84.

The positioning of the individual doors in their respective channels isan important feature of thisinvention and will be described in detail;however, since all the doors are similarly arranged and mounted, adescription of one door assembly will serve as a description of all.Consequently, the assembly of door 38 will be described as follows:

The door 38 is removable from the framework and is insertable by firstinserting its upper edge 86 under the upper frame member 24 and into thechannel 54. This is generally done with the door in about the center ofthe case rather than at the end. After the upper edge 86 has beenproperly inserted, the lower edge 88 is in serted into place with thegrooved rollers 90 (to be hereafter more fully described) engaged withthe corresponding rail 92 on the frame portion 32.

Positioned within the channel 54, as well as within each of the otherchannels, is.a metal strip 94 which is resiliently biased into a coil96. The strip 94 is usually constructed of stainless steel orhigh-carbon spring steel and is stressedincrementally along its lengthrather than cumulatively as in ordinary springs. Consequently, the strip94 maintains a constant resistance to uncoiling throughout its entiredeflection.

The strip 94 is secured at 98, as by adhesive, welding, soldering,bolting or the like, between a finger 100 hinged at 102 to a plate 104and a finger 106 extending into a slot 108 is partially covered by thefinger 100 but is of substantially greater length than the finger 106 sothat even when the finger 106 is in fully extended horizontal position,a space will remain between its edge and the edge of the slot.

Positioned under the plate 104 is a plate 110 and below this plate 110is provided a bumper bar 112 of preferably resilient material. Theplates 104, 110 and bumper bar 112 are all held in assembledrelationship and connected to the top wall of channel 54 by bolts 114and nuts 116. A leaf spring 118 is connected by welding, rivets or thelike to the top wall of channel 54. This spring bears against the finger106, as at 122, urging the finger 106 into the slot 108.

The door 38, similarly to all the other doors 40, 42 and 44, is providedwith a pair of slots 124 in each of which is journaled a grooved roller90.

In operation, with the door 38 removed, the spring coil 96 occupies mostof the width of channel 54 (as shown in Fig. To insert the door 38, theupper edge 86 of the door is inserted under the frame member 24 and intochannel 54 from below; the door generally being inserted midway of thelength of the channel (as shown in Fig. 4). When this is done, the dooredge 86 acts to lift the coil 96 against its bias into contact withfinger 106. Finger 106 flexes through slot 108 while yet acting as aguard member to prevent binding of coil 96 in the slot 108 and toprevent damage to the somewhat delicate spring. The finger 106 under thetension of spring 118, also serves another purpose. During the lastfractional portion of the closing movement and while the door is inclosed position, because of the nature of the spring coil 96, any slightobstruction or jar would cause the door to slide back slightly againstthe force of the coil. This would be especially undesirable in the caseof a refrigerated cabinet where the heat of the room would enter.However, the force of the spring 118 on the finger 106 acts as acounterforce to resist this opening movement until a positive openingforce of sufficient extent is applied.

After the upper edge of the door has been inserted, the lower edge ofthe door is lifted over the bar 32 until the rollers 90 engage over therail 92. The door 38 is then pushed to the right (as viewed in Figs. 4,5 and 6) until the trailing edge of the door clears the coil 96. Whenthis happens, the coil 96 moves down into position behind the trailingedge of the door (as shown in Fig. 5). Thereafter, whenever the door ispushed back into open position, it pushes back the spring coil 96 whichuncoils the strip 94 (as shown in Fig. 6). When the door is thenreleased, the spring strip 94 acts to automatically move the door backinto closing position, in which position its forward edge contacts aresilient bumper strip 125. This closing movement of the door iseffected gently and easily because of the heretofore explained constanttension of the spring strip 94.

When the door is removed in reverse fashion to the manner in which itwas inserted, the bumper bar 112 prevents the spring coil 96 frombouncing back beyond its original position.

In the preferred embodiment of the invention, illustrated in Figs. 1 to.5, 9 and 10, the upper edge 86 of the door is slightly inclined from ahigh point at the trailing edge to a low point at the forward edge; thisinclination being somewhat exaggerated in the drawings for greaterclarity. One reason for this is to permit easy insertion of the doorwhile yet permitting the trailing edge of the door to engage the coil 96properly. In further explanation, the trailing edge of the door 38should extend to a height above the center line of the coil so that,when the door is pushed back against the coil, it will push it backstraight. If it were below the center line of the coil, there would bean inclined vector force which would tend to push the coil into the slot108 and cause binding. On the other hand, there should be sufiicientclearance to enable the door to be properly and easily inserted into thechannel 54 without pushing the coil 96 too strongly against the finger106. By providing the inclined edge 86 on the door, the door is insertedin such position that the lower central portion of the door firstengages coil 96 and then as the door is initially pushed into its closedposition, the coil rides gradually up on the cam-like inclined edge 86until it falls down on the other side of the trailing edge of the door.

Another function provided by this tapered upper edge construction isthat after the upper edge has been inserted, and while the lower edge isbeing inserted, the higher end of the door acts as a fulcrum to permiteasier insertion of the opposite end of the door.

The above-described tapered upper edge construction of the door permitsthe door to be made without the very fine tolerances which would benecessary if the door were made perfectly rectangular and yet with therequired height of the trailing edge together with the sufficientclearance necessary for easy insertion. In this manner, the expense andtime of manufacture is considerably reduced.

Instead of making the upper edge of the door entirely inclined, as inFigs. 4 to 6, a door 200 may be used, as illustrated in Fig. 7, wherethe upper edge 202 is straight but a cam portion 204 is provided at thetrailing edge. This door 200 functions similarly to door 38 except thatinstead of the upper edge 202 being entirely tapered, it can be madesubstantially straight while the cam portion 204 can either be madeseparably and then attached or made integral with the door frame in thefirst instance.

In Fig. 8 there is shown a door 300 which is similar to the other doorsdescribed except that it is has a perfectly straight upper edge 302.This edge 302 is somewhat more efficient than the others since, by thisconstruction, the door can be inserted evenly at any position relativeto the spring coil; however, the cost and difficulty of manufacture ofthis straight edge type of door is much greater than the others becauseof the fine tolerances required.

As illustrated, the doors 38 and 40 are provided for the upper portionof the display case and the doors 42 and 44 for the lower portionthereof. The doors 38 and 40 are arranged to close in oppositedirections as are also doors 42 and 44. Therefore, the spring strip 94of channel 54 is biased into its coil 96 in an opposite direction fromthe spring strip in channel 56 (as best indicated in Fig. 10) while thesame is true of the corresponding spring strips in channels 58 and 60where the strips are also biased into their respective coils fromopposite directions.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed as the invention is:

1. In a self-closing door arrangement, a frame comprising upper andlower track means, said upper track means comprising a channel memberhaving a front wall, a rear wall and a top wall, an aperture in said topwall intermediate its length, a finger hinged to said top wall at oneside of said aperture, said finger being of smaller length than saidaperture, a spring on said channel member resiliently urging said fingerdownwardly through said aperture, a spring strip resiliently mounted insaid channel member and longitudinally biased into a coil underlyingsaid finger, a door panel removably insertable into said frame betweensaid upper and lower truck means, said coil being positioned to bepushed radially upward against said finger by the upper edge of saiddoor panel when said door panel is inserted into said channel member,and said coil being resiliently urged into a position wherein it abutsagainst the trailing edge of the door panel when said panel is movedaway therefrom longitudinally of said channel member.

2. In a self-closing door arrangement, a frame comprising an upperchannel member and a lower rail, said door panel having grooved rollerson its lower edge positioned to movably engage said rail, said upperchannel member having a front wall, a rear wall and a top wall, anaperture in said top wall, intermediate its length, a finger hinged tosaid top wall at one side of said aperture, said finger being of smallerlength than said aperture, a spring on said channel member resilientlyurging said finger downwardly through said aperture, a spring stripresiliently mounted in said channel member and longitudinally biasedinto a coil underlying said finger, a door panel removably insertableinto said frame between said upper and lower track means, said coilbeing positioned to be pushed radially upward when said door panel isinserted into said channel member, said coil being resiliently urgedinto a position wherein it abuts against the trailing edge of the doorpanel when said panel is moved away therefrom longitudinally of saidchannel member, and a flexible bumper bar underlying said top wall in aposition to be engaged by said coil when said door panel is removed.

3. The arrangement of claim 1 wherein said door panel comprises agenerally rectangular frame enclosing a transparent plate.

4. The arrangement of claim 1 wherein said door panel comprises agenerally rectangular frame enclosing a transparent plate, the upperedge of said frame being tapered from one end to the other thereof.

5. The arrangement of claim 1 wherein said door panel comprises agenerally rectangular frame enclosing a transparent plate, the upperedge of said frame being substantially straight and having a cam portionprovided at one end thereof.

6. A track means for slidable doors comprising an elongated channelmember, an aperture intermediate the ends of said channel member, afinger of smaller length than said aperture hinged to said channelmember and spring-pressed into said aperture, a spring strip having oneend connected to said channel member adjacent said finger and biasedinto a coil underlying said finger, and a bumper bar connected to saidchannel member below said finger in a position to be normally engaged bysaid coil when said coil is free from tension.

7. A self-closing door arrangement comprising a housing, an opening insaid housing, a channel track on at least a portion of the innerperiphery of said opening, said channel track being defined by a striphaving two vertical walls integral therewith, the lower edges of saidvertical walls defining the corresponding elfective periphery of saidopening, a door panel removably positioned in said opening with one edgethereof extending into said channel track beyond said elfectiveperiphery, a spring strip in said channel track, said spring strip beingresiliently biased into a coil, said coil normally extending toward saideffective periphery to a position downwardly of the position of said oneedge of said door panel when said door panel is in said opening, saidchannel track having means thereon to permit said coil to be pressedradially back from said lower edges of said vertical Walls when pressureis applied radially to said coil so that said one edge of said doorpanel acts to engage said coil and push it radially back from its normalposition when said door panel is inserted into said opening in adjacencyto said coil, and said cell acting to return to its normal position whensaid door panel is moved away from contact therewith.

8. The arrangement of claim 7 wherein said spring strip is incrementallystressed along its length to provide a constant linear tension thereon.

9. A self-closing door arrangement comprising a housing, a rectangularopening in said housing, track means on at least a portion of theperiphery of said opening, said track means comprising an upper channelmember defined by an upper strip having two vertical walls integraltherewith, a guide element generally parallel to but spaced from saidupper channel member, a rectangular door panel removably positioned insaid opening and having one edge removably engaged in said channelmember, and the opposite edge having guide means releasably engaged withsaid guide element, a spring strip in said channel member, said springstrip being resiliently biased into a coil, said coil being resilientlybiased into a normal position within said channel member adjacent thelower edges of said vertical walls, said door panel being of such widththat when it is positioned in said opening one edge thereof extends intosaid track means beyond the corresponding peripheral plane of said coilwhen said coil is in its normal position so that when said one edge isinserted in said track means adjacent said coil, said one edge engagessaid coil and pushes it radially back from its normal position, and saiddoor panel having a length smaller than the distance between said coiland one end of said opening whereby, upon linear movement of said doorpanel toward said one end of said opening, said door panel is disengagedfrom said coil which thereupon moves back into its normal position.

10. The arrangement of claim 9 wherein said guide means comprises atleast one grooved roller and said guide element comprises a rail, saidroller being movably engaged with said rail when said door panel ispositioned in said opening.

References Cited in the file of this patent UNITED STATES PATENTS1,181,331 Metzger May 2, 1916 2,085,832 Schochet July 6, 1937 2,118,213Malott May 24, 1938 2,695,968 Welch Nov. 30, 1954 2,732,594 Adams Jan.31, 1956

